“Bob Dylan: A Spiritual Life” by Scott M. Marshall landed that diverse quartet. The author credits his source’s enduring appeal more than any writing flourishes. It’s also a testament to Dylan’s continual search for spiritual meaning.

Christian? Jew? Agnostic? An inquisitive soul seeking answers to our biggest questions? Perhaps it’s all of the above. And that search continues to fascinate us. For those folks, or simply anyone who admires one of western civilization’s premier songsmiths, “A Spiritual Life” is a must-read.

“A Spiritual Life” captures the singer’s longing for larger truths. His trek proves as inscrutable as the rest of his public persona. It’s alive and well all the same – in his lyrics, his records and via his endless touring.

Marshall interviews a variety of sources in the singer’s mercurial orbit, including President Jimmy Carter. He lets them all share how Dylan’s faith journey impacts his art and humanity.

The Inscrutable Bard

Dylan is the opposite of an open book, and famously so. Yet Marshall rallies enough material to support the theory that he remains one of music’s most soulful troubadours.

He once appeared at the Wailing Wall wearing a yarmulke. He studied at a Bible school in California. He released three Gospel-themed rock albums at one point (“Slow Train Coming,” “Saved” and “Shot Of Love”) and confused fans by playing their tracks over his greatest hits in concert.

He publicly retreated from that hard-faith detour but didn’t renounce his faith. Spirituality remained a critical part of his songwriting kit. It still does.

Along with way, the playful poet spoke with passion on the subject. He told Rolling Stone back in 1984, as plain as he could possibly speak, about where he stood on life after death.

“There’s no way you’re gonna convince me this is all there is to it.”

Generational Divide

Marshall didn’t come of age during the Flower Power era. He caught up with Dylan’s earliest material as a grown man. He thinks that gave him an advantage when writing the book.

“I could be his son, age-wise,” he says. “Some of the folks of his generation came up with him at the same time and had different thoughts on him. I just was curious about his spiritual journey. It’s not just me forming opinions out of nowhere. I let his own voice speak for himself.”

Artists fortunate enough to sing with Dylan also appear in “A Spiritual Life.” Take Regina McCrary, a singer who toured with Dylan in the late 1970s during Dylan’s Gospel period.

“When I interviewed her first in 2000 she had never been tracked down [on the subject],” he says. “She just has some great stories.”

‘New’ Dylan on the Way

Marshall, who may examine Woody Allen’s expansive film resume for his next book, says the singer still has some surprises in store for fans. The author says we’ll see a fresh “bootleg series” release from Dylan in November tied to his Gospel touring.

Dylan may be 76, but Marshall insists he’s not creatively done yet. In fact, he says Dylan isn’t so far removed from the singer Marshall first saw live back in 1990. The future author had “nosebleed seats” and “too much liquor” at the time. He was in his 20s watching a 40-something legend at work.

Marshall still remembers how the show opened – with ZZ Top’s “My Head’s in Mississippi.”

That’s just Dylan, then … and now. He’s a performer who attracts the devoutly religious as well as atheists with his songbook and ability to surprise.

“There’s really no telling what he might do on stage or with an album,” he says.